A method of fixing a magnetic disk in a disk apparatus has been disclosed in Japanese Patent Laid-Open No. 2001-291301, for instance, where an upper surface of a flange which is formed at a lower side of a hub constitutes an annular disk support on which magnetic disks and a spacer are alternately superposed, with a clamp disposed on top, and a clamp screw is tightened so that the clamp is deformed by an applied tightening force, imposing a clamping force on the magnetic disk to thereby fix the magnetic disk.
It is also known that in the above-described structure an elastic member having a large coefficient of friction, such as one made of polyurethane rubber, is interposed between the magnetic disk and the spacer, as disclosed in Japanese Patent Laid-Open No. H6(1994)-28752, for instance. [Patent Document 1] Japanese Patent Laid-Open No. 2001-291301 [Patent Document 2] Japanese Patent Laid-Open No. H6(1994)-28752